212187209 has 8 divisors (see below), whose sum is σ = 230866440. Its totient is φ = 193844736.

The previous prime is 212187197. The next prime is 212187211. The reversal of 212187209 is 902781212.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 54760000 + 157427209 = 7400^2 + 12547^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 212187209 - 2¹⁶ = 212121673 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (212187299) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 82874 + ... + 85395.

It is an arithmetic number, because the mean of its divisors is an integer number (28858305).

Almost surely, 2^212187209 is an apocalyptic number.

It is an amenable number.

212187209 is a deficient number, since it is larger than the sum of its proper divisors (18679231).

212187209 is a wasteful number, since it uses less digits than its factorization.

212187209 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 168379.

The product of its (nonzero) digits is 4032, while the sum is 32.

The square root of 212187209 is about 14566.6471433889. The cubic root of 212187209 is about 596.4486594014.

The spelling of 212187209 in words is "two hundred twelve million, one hundred eighty-seven thousand, two hundred nine".